Regenerating
bushland can involve some or all of the following techniques:
- Weed
control: Careful handweeding, especially around existing
native vegetation. Techniques are described by the Bradley sisters,
which entail starting in areas of best vegetation and gradually
working outwards, never overclearing, creating minimal disturbance
and always following up in successive seasons.
- Herbicides
are commonly used, either as a contact spray or as a stem injection.
Their use must always be carefully considered as there is a risk
of general environmental contamination.
- Solarisation:
Smaller areas can be covered by plastic for periods of time to
kill existing plants. In very weedy areas this may be repeated
after a time to allow for regermination of weeds prior to mulching
and/or planting.
- Slashing:
This is part of a regular management procedure particularly for
grasses and depends on seasonality. The aim here is to reduce
the volume of weed seed entering the environment.
- Planting:
Usually tubestock is used, however, smaller plugs or even mats
of plant material supplied from local sources can be used. The
choice of species is important. In more degraded areas vigorous
larger tree and shrub species are required, in unsettled areas
fast colonisers are useful, such as herbs and grasses. In some
areas, such as semi-intact grasslands, slashing may become a key
regenerative technique, so planting may become a hindrance. Planting
nitrogen fixing large wattles such as Black Wattle (Acacia
mearnsii) may help this environment, whilst still allowing
slashing management to be carried out. Planting recharge areas
in salt affected areas can lower the water table.
- Fencing:
The exclusion of stock, feral animals and people is often important.
Fencing simply to delineate a regeneration site may be useful.
- Brushing:
The placement of branches with or without seed over exposed areas
can significantly minimise erosion processes, thereby allowing
microclimates for seedlings to establish. This is particularly
useful in coastal areas, but the concept of establishing smaller
favorable sites for regenerating plants within a larger area is
a good one.
- Mulching:
The quality of the mulch is essential here, especially when being
used in high quality areas. Material from compatible native vegetation
and free of weeds is important. In good areas it should be used
sparingly, but is very useful where large areas have become exposed
and planting is being done. Mulch creates a dynamic relationship
with the soil and even attracts fungi from the air. It should
generally consist of a mixture of plant species and contain leaves,
sticks and small limbs, creating good habitat for ground fauna.
- Scalping
is a fairly extreme method which physically removes a thin layer
of topsoil and weed material contained within it. This is stockpiled
and the site is then planted or seeded and mulched.
- Direct
seeding: This entails spreading or drilling seed at a
favourable time to densely recolonise the site. In some ways this
is the most natural method of re-establishing plants. Planting
tubestock can be viewed as direct seeding in some circumstances
when the plants are expected to seed in the first year and broadcast
onto similarly receptive sites. Problems with direct seeding are
the lack of availability of local seed as a low germination result
is often achieved and combating weed competition, especially without
the use of residual herbicides.
- Slashing
can be timed so that seeding of introduced species is prevented,
whilst seeding of indigenous species is encouraged. Slashing may
be required for fire safety, otherwise it may be done less frequently.
The height of slashing will also affect the ability of certain
species to flower and set seed thus influencing the make up of
the communities.
Taken from the web-site of the Association
of Societies for Growing Australian Plants ASGAP
|